1. Field of the Invention
This invention relates to knitted fabrics with excellent warmth-keeping and water-absorbing characteristics, and to a process for manufacturing the same.
2. Description of the Prior Art
Autumn and winter underwear is principally made of cotton. Although wool, acrylic and polyester fibers have also been employed for this purpose, no product has yet been created which satisfies all the requirements such as hand, warmth retention, stretchability, stretch recovery, anti-pilling property, water absorption, ease of drying, dimensional stability after laundering, whiteness and its retention, and static charge dissipation, and is low in cost at the same time. Fabrics made of natural fiber are favorable in moisture absorption but is poor in dimensional stability, whiteness and other properties, while those made of synthetic fiber are insufficient in anti-pilling and moisture-absorbing characteristics though excellent in dimensional stability and ease of drying after laundering.
Use of knitted fabrics made of polyester fiber as sportswear and underwear has recently been proposed, for example, in Japanese Patent Kokai Nos. 60-94682 (May 27, 1985), 60-246873 (Dec. 6, 1985) and 61-28073 (Feb. 7, 1986). Any of these fabrics is too poor in anti-pilling property to be put to use as underwear which needs frequent laundering, and does not satisfy consumers' requirement also in terms of comfort in wear such as warmth retention, etc. For example, the woven and knitted fabrics described in Japanese Patent Kokai No. 61-28073 (Feb. 7, 1986) are composed of polyethylene terephthalate copolymer fiber containing 0.8 to 1.8 mol% of sulfo-isophthalic acid and rendered hydrophilic, and have a dual structure with a cover factor ratio (front face to back face) less than 0.8. Fabrics of this type form pills after several times of wear and laundering. The pills thus formed tend to attach to other textiles during laundering and to intertwine with pieces of fiber released from these textiles, degrading their utility value. This trouble is particularly marked when fabrics of different colors are laundered together. In addition, pilling adversely affects warmth-keeping characteristics as well as the feel to the skin, making the affected fabric unsuitable for use as underwear.
Thoroughgoing studies on the characteristics required of garments kept in direct contact with the skin, particularly underwear, have led us to confirm that the characteristics listed below are essential to the development of new garments, particularly for underwear, with excellent properties not to be found in conventional products. This invention was accomplished based on these findings.
(1) Favorable feel of warmth upon contact with the skin. PA0 (2) High stretchability to ensure adaptability to the skin and ease of wear. PA0 (3) Sustained feel of warmth during wear. PA0 (4) Rendered hydrophilic to minimize stuffy feeling during wear, said hydrophilic characteristics being durable to laundering and giving no feel of coldness. PA0 (5) Little tendency of forming pills. PA0 (6) Soft in hand and mild to the skin. PA0 (7) Whiteness maintained over long periods, giving a feel of cleanliness, with little tendency of yellowing and discoloration. PA0 (8) Little tendency of generating static charges which can cause disagreeable electrostatic shocks upon putting on or taking off. PA0 (9) Easy to dry after laundering with little deformation.